Fuel pump



Nov. 19, 1929. a A. CATTENDUY 1,736,242

FUEL PUMP Filed Jan. 25, 1924 8 Sheets-Sheet l Nbv. 19, 1929- A. 'c. ATTENDU FUEL PUMP Filed n- 1924 8 Sheets-Sheet 2 1929. A. c. ATTENDU 1,736,242

FUEL PUMP File an- 5, 1924 8 Sheets-Sheet 3 NW; 19, 1929. A. c. ATTENDU 1,736,242

FUEL PUMP Filed Jan. 25, 1.924 8 Sheets-SheetO 4 Nov. 19, 1.929a A. c. ATTENDU 1,736,242

FUEL, PUMP Filed Jan. 25, 1924 8 Sheets-Sheet 5 Nov. 19, 19298 A. c. ATTENDU 1,736,242

. FUEL PUMP Filed Jan. 25, 1924 8 Sheets-Sheet 6 Andre ew attozM eq Nov. 19, 1 929. A. c3. ATTENDU' 1,736,242

FUEL PUMP I Filed Jan. 25, 1924 s sheets-sheet 7 3 wue nto z Nov. 19, 1929.. A. c. ATTENDU FUEL PUMP Filed n- 1924 8 Sheets-Sheet 8 Wk M Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE FUEL PUMP Application filed January 25, 1924. Serial No. 588,591.

practice, to accelerate injection through the agency of compressed am This arrangement owing to its complicated mechanical details has proved objectionable and it is therefore one of the objects of this invention to provide for the operation of the injector and the injection of a solid fuel in a single operation by increasing the pressure normally existing in the supply circuit of the pumping mechanism.

Another important object of this invention is to provide a fuel pumping mechanism including means for changing within predetermined limits the time when the injection 2 offuel should commence and also for determining the amount of fuel injected.

Other objects of this invention are to produce a pumping mechanism permitting independent or simultaneous variation-in both the quantity of and time at which the fuel injection occurs, and finally to design a fuel pump which is accurate, devoid of compli cated parts and so constructed as to permit convenient disassembly when occasion de- 'mands.

With these and other objects in view, this invention consists in certain novel details of construction, combination and arrangements of parts to be more specifically hereinafter set forth and claimed.

Briefly stated, this invention embodies a fuel supply circuit, means for developing and maintaining an approximately constant circuit pressure. means for increasing this pressure at'predetermined intervals to operate the injector and effect fuel injection under the requisite-pressure, and a timing device including a mechanism to independently or simultaneously yary either the amount of fuel injected or time at which such injection should commence.

Referring to the accompanying drawings, in which the corresponding parts are designatcd by similar reference characters:

Fig. 1 is a top plan illustrating the general assembly of engine and fuel injecting mechanism.

Fig. 2 is a sectional View partly in elevation illustrating the position of the pump with respect to the engine. i

Fig. 3 is a fragmentary sectional assembly partly in elevation of the pumping mechanism and engine.

Fig. 4 is a sectional View of the fuel injectlng mechanism in the plane of the pressure pumps. 1 Fig. 5 is a sectional view partly in elevation on the line 5-5 of Fig. 1.

Fig. 6 is a transverse sectional View partly in elevation of the fuel injecting mechanism.

Fig. 7 is a horizontal section taken on the line 77 of Fig. 6.

Fig. 8 is a fragmentary sectional view partly in elevation of thefuel injecting and timing mechanisms.

Fig. 9 is a sectional view taken on the line 99 of Fig. 6.

In the illustrated embodiment characterizing this invention there is shown in Figs. 1 to 3, of the drawing an engine such as that described and claimed in pending application Serial No. 671,181, and which for the present purposes may be briefly outlined as a cylinder block 1, a head 2,"and power and pumping cylinders 3 and 4, respectively, the

head and block being suitably water jacketed for obvious reasons. Each power cylinder 3 contains a piston 5 of the usual trunk form, which is elongated and formed with its lower end 6 of enlarged diameter to provide a piston head forthe-pumping cylinder, making one.

piston function for both cylinders.

Operatively associated with respect to the I pumping cylinder is an air'intake 7 through which air isdrawn for compression. Intermediate eachpair of cylinders is a passage 8 controlled by an intake valve 9, to permit the air undercompression to be transferred to ad joining working cylinders to scavenge and likea wise establish a predetermined precompression pressure regulated through the medium of exhaust valve 10. Obvously air may be admitted at the bottom of the cylinder and allowed to escape with exhaust gases through an exhaust valve at the top of the cylinder.

To effect an injection of fuel into the power or working cylinders, head 2 is provided with injectors 11, such as that described and claimed in my co-pending application, Serial No. 688,815, and hereinafter to be referred to. Each injector is connected to one end of a supply line 12, the opposite end of which is connected to the fuel injecting means desig nated in its entiety as 13. The respective injectors for the purpose of this description may be said to embody a suitable housing, in which is positioned a reciprocatory plunger 13 reduced at its lower extremity to form a needle valve 14 for cooperation with seat 15. A passageway 16, formed in the injector communicates at one end with injector line 12 and at its opposite end with an annular space 17 underlying a shoulder 18 on the lower, end of plunger 13. A balancing spring 19 confilned between the upper end of plunger 13 and cap 20 serves to normally maintain the valve in its seated position, the upward throw. or lift of plunger 13 being regulated by a stop 21 adjustable in the aforementioned cap 20.

To facilitate further discussion of the pump, it shall be considered in the order of its components:

(A) Means for effecting fuel'injection;

(B) Mechanism for varying the quantity of fuel injected and (C) Timing means.

Means for effecting fuel injection actuated in a manner hereinafterto be de-- Plungers 29 functioning in bores 27 con-' stitute the pressure pumps of the mechanism by which the requisite fuel supply pressure is developed and maintained.

The upper extremites of bores 27 terminate in valve chambers 30 having outlet ports 31 opening into passages 32 leading to supply reservoir Check valves 34 suitably positioned in the valve chambers 30, when unseatbores 27 and passages 32 via ports 31.

The fuel reservoir 35 communicates via passage 36 with distributing chamber 38.

Depending from the head immediately to the rear of the tubular extensions forming the pressure pumps are another series of similarly formed dependents 39, four in number, and likewise arranged in spaced and aligning relation. Each of the dependents 39 is formed with a bore 40 in which is reciprocally mounted a plunger 41, the lower end of which is actuated in a manner hereinafter to be described. The plungers 41 functioning in their respective bores furnish a means ,by which the pressure in the supply circuit is increased to elevate the valves 14 in the injectors 11 and thus effect the injection of fuel into the power cylinders. The upper ends of the pump bores 40 are in communication with the distrubut--' and a spring interposed between the head and plunger.

To actuate the plungers 29 of the pressure pumps, a slidable-sleeve 52 is telescopically positioned on each of the tubular dependents 28; the lower extremities of plungers 29 and those of the sleeves being pivoted to crank arms 53 through the wrist pin connection 54. Crank arms 53 are carried by the eccentric straps 55 which are positionedon the shaft 56 with a 120 angular displacement.

To operate shaft 56 it is provided at one end with a gear 57 driven through gear 58 keyed to shaft 59.

To operate the plum ers of the delivery pumps, each of the tu ular dependents 39 have their lower ends in telescopic engagement with a slidable sleeve 60, the lower end of which is formed with a ta pet in the nature of the cross head 61, whic is connected to plunger 41 by wrist pin 62. The crosshead 61 is formed at its opposite ends with openings 63 to receive guides 64, the upper ends of which are threaded in the under surface of the pump head 23. Springs 65 interposed between crosshead 61 and the pumphead 23 function to quickly return the plunger to its initial position. v

Cams 66 keyed to shaft 59 engage the crossheads .61 to give the requisite movement of the plungers. Owing to the peculiar shape of the cams, they will imparta smart kick to.the delivery plungers uponinitial contact.-

Shaft 59 is connected to and driven byshaft 68 of the timing mechanism hereinafter to bereferredto, through a coupling 69 as shown in Fig. 8 of the drawings.

To overcome the effect of lateral stresses on the sleeves 60 due to impact of the actuating cams 66, crosshead 61 is formed with a wear plate 7 O which is slidable over the surface of-complemental plate'7l laterally offset from the base of the pump, as clearly shown in Fig. 6. Each of the .sleeves 60 is also formed at its upper end with projections 73 adapted to be engaged by fingers 74, carried by shaft 75 journaled longitudinally of the pump and at the rear of its base.

The function of fuel pump and injector valve wherein it is confined'under a predetermined pressure maintained approximately constant by the adjustable relief valve 48 in chamber 45. With this arrangement, should the normal pressure of 1500 lbs. be exceeded, the fuel acting on the plunger 48 will cause the latter to uncover the outlet 46 communieating with return pipe 47. Owing to the triangular configuration and the disposition of the apex of outlet 46 with res ect to the plunger, as the pressure of the uel on the plunger increases, it will uncover a greatly increasing area of the outlet and thus permit an increase in the quantity of fuel escaping.

From reservoir 35, fuel passes through passage 36, into distributing chamber '38 and thence via check valve 43 and passage 42, through nipple 43' and into injector line 12 and thence into injector passage 16 of the injector to annular space 17. The pressure of oil in the fuel reservoir and hence in the circuit, just established is approximately 1500 lbs.- per square inch which is maintained constant by the relief by-pass hereinbeforomentioned. The oil when under its normal pressure of 1500 lbs. is prevented from entering the cylinder through the injector by means of balancing sprin 19 retaining the injector valve in seated position. At the time of fuel injection, the fuel pressure is increased upon ascent of the plunger 41 of the delivery pump.

"and thereupon t ancing spring 19. As the plunger of the delivery pump descends on the return stroke v the supply circuit to elevate the injector and effect an injection of fuel.

Mechanism. for varying the quantity of fuel injected a It is necessary to vary the quantityof fuel injected in order to compensate for various load requirements and for this reason the fingers 7 4 on'shaft 75 are arcuately movable and engage the projections 73 carried by the slidable sleeves of the delivery pumps, to-

enable the sleeves to be raised or lowered. As these sleeves carry the plungers of the delivery pumps, the stroke of the plungers will be accordingly increased or diminished dependent on the exigency of the situation. To actuate the fingers, shaft 75 is formed with a segmental rack 76, meshing with an appropriately j ournaled worm 77, the free endof which is formed with a worm gear 78, adapted to mesh with the worm of shaft 79 'journaled longitudinally of the pump and extended at both ends exteriorly of the pump casing.

One extremityof shaft 79 may be provided with an operating handle (not shown) so that it may be rocked in its bearings and through means of theinstrumentalities noted the delivery pump sleeves vertically adjusted to vary the stroke of the plungers and therefore the quantity of fuel injected.

Assuming that it is desirable to merely increase the quantity of fuel injected, without changingthe time fuel injection should commence, it is manifest, since the variation in the quantity of-fuel injected is accomplished by lowering the sleeves, the cams actuating such sleeves, must be simultaneously reset to maintainthe same relative position between cams and sleeve tappets with which they contact and thus retain the time of fuel injection constant. For this purpose the free end of the shaft 79, hereinbefore referred I to is extended and externally threaded to form a follower shaft 80, which coacting with a timing mechanism 81 hereinafter referred to, rotates the previously mentioned shaft 68 journaled at one end in the timin mechanism and coupled at its opposite en to the cam shaft 59 by con ling 69, so that the shaft 59 he cams 66 keyed thereon are rotated through an angle suitable to maintain the same relative position between the cams and the tappets which they engage at the beginning 0 injection strokes.

Timing mechanism In order to vary the time at which the injection of fuel begins, without changing the quantity of fuel injected and inversely, to change the quantity, the time of injection remaining constant or altering both simultaneously, the timing mechanism 81 is provided, comprising a suitable casing 82 in which is rotatably journaled a drum 83 formed at one end with a suitably journaled tubular exten-- sion 84. The opposite end of the drum 83 collar 91, and is carried by the control rod-' 94, slidable in the casing 92, as shown in Fig. 8 of the drawings.

Telescopically positioned in the sleeve 90, is a longitudinally movable sleeve 95, formed externally with curved splines 96 which coact with those of sleeve 90, to effect rotation of sleeve 95, when the latter is moved longitudinally into or out of the former. Sleeve 95.is provided at its free end with a collar 97 and is keyed to shaft 68 by the keys 98 filling suitably arranged key-ways in the sleeve. The'collar 97 of sleeve 95 is embraced by a yoke 99, carried by a longitudinally shiftable rod 100. One end of this rod is secured in a suitable manner to move with a follower 101, through which is threaded the follower shaft 80, hereinbefore mentioned.

Having described the structure of the timing mechanism, its operation is as follows:

As the shaft 79 is rotated through a predetermined angle and in a given direction, it will through the worm gear 78, worm shaft 77, segmental rack 76, shaft 75 and finger 74 lower the sleeve ofthe delivery plungers '41 and in consequence increase the amount of fuel injected. At the same time the cams 66, as viewed in Fig. 6, are shifted clockwise a distancepredetermined with respect to the extent to which the sleeves 60 are lowered to,

' thereby maintain the same time of contact/beapparent that as follower shaft 80 rotates, the follower 101 traveling thereon acts through rod 100,.- yoke 99 and collar 97 to move the sleeve 95 in or out of the non-rotatable sleeve 90 dependent upon the direction of rotation of shaft 80. Through this movement of sleeve 95 and the cooperation of splines 92 and 96, the sleeve 95 and consequently shaft 68 are rotated to effect the proper setting of the shaft 59 and cam lifts 66.

If, on the other hand, running-conditions of the engine are such that it is merely desirable to vary the time at which injection should begin, then control rod 94 is moved longitudinally relative position of the cams 66 with respect to. the tappets 61 so as to advance or retard the time of contact between the cams and tap-,

pets, dependent upon the direction in which said rod has moved. Specifically this variation in the setting of the cams is accom-.

time at which fuel injection sh'ould begin, as

well as the quantity of fuel injected, control rod 79 is rotated to shift the tappets 61 in a stroke of delivery plungers 41. Inasmuch as varying the stroke of plungers '41 to control the quantity of fuel delivered simultaneously acts to adjust the setting of the cams as previously stated it becomes necessary. to offset this automatic adjustment by operating control rod 94 so that the position of the cams with respect to the tappets'6l may be independently adjusted to give the desired timing of injection.

In conclusion, it is evident that the forein its bearings to shift they manner hereinbefore stated, thus varying the j going structure furnishesa mechanism by a which the fuel supply circuit is established and maintained with a normal pressure of approximately 1500 lbs. per square inch, that varying amounts of fuel may be injected and the injector actuated by a periodical increase in the normal pressure of the sup ly circuit and the time of fuel injection may lue readily varied to meet the engine load requirements.

What I claim, as my invention is:

1. A fuel pump comprising a delivery plunger, a cam for operating said plunger in one direction, means for operating said plunger in the opposite direction,'a camshaft carrying said cam, means for regulating the stroke of the plunger and simultaneously rotating the cam shaft to change the setting of the cam in such manner as to vary the quanstop for varying the suction stroke of the tity offuel delivered by the plunger without chan ing the time of delivery, andmeans for rotating the cam shaft to eflect an independent ad'ustment of the cam when it is desired to change the time of delivery forany quantity of fuel within the delivery capacity of the pump.

2. A fuel pumpcomprising a delivery plunger, an operating cam therefor, mechanism for varying the stroke of the plunger, mechanism for varying the angular displacement of the cam with reference to the plunger,

- means for operating both mechanisms simultaneously to vary the quantity of fuel delivered by the plunger without changing the time of plunger operation and means for operating the cam displacing mechanism in dependently to change the time of delivery for any given quantity of fuel.

3.- A pump comprising a delivery lunger, an operating cam therefor, an ad iustable plunger, mechanism for varying the angular displacement of the cam with reference to said plunger and means for changing the position of said stop' including provision for simultaneously operating the cam displacing mechanism whereby the quantity of fuel delivered by the plunger is varied without varying the time of delivery.

4. A pump comprising a delivery plunger, an operating cam therefor, mechanism for varying the stroke of the plunger including a longitudinallymovable element,a pair of telescoping sleeves provided with interengaging curved splines adapted to produce rotation of one sleeve in response to relative longitudinal movement of .the sleeves, means controlled by said element for effecting the aforesaid relative longitudinal movement of the sleeves and means controlled by the resulting turnin movement of the rotary sleeve to vary the angular displacement of said cam with reference to the plunger to maintain a constant time of injection irrespective of the plunger stroke variations.

5. A pump as recited in claim 4 including provision for effecting relative lon itudinal movement of said sleeves indepen ently of said element in order to change the time of plunger operation for any given stroke of the plunger. w

6. A fuel pump comprising a' delivery plunger, an o erating cam engageable therewith, means or adjusting the stroke of the plunger and means for advancing or retarding the time of contact between the plunger and the cam lift simultaneously with the adjustment of the plunger stroke so as to main-* tain the same timing of injection.

In'testimony whereof I hereunto aflix my signature.

ANDRE c. ATTENDU. 

